摘要:

Bone scintigraphy is very sensitive in detecting metastases in an early stage, when changes in osteoblast function precede morphologic changes. In many oncologic situations, however, osteoarticular abnormal changes seen on the bone scan are not caused by tumor infiltration. They may be due to tumor associated conditions, such as carcinoma polyarthritis and hypertrophic pulmonary osteoarthropathy. They also may be due to therapy-associated conditions, such as the flare effect on metastases due to hormonal treatment, chemotherapy or radiotherapy, and osteonecrosis as a complication of radiotherapy or the use of corticosteroids.The introduction of Colony Stimulating Factors (CSF) to reduce myelotoxicity have allowed higher doses of chemotherapeutic agents to be administered. Currently, there is research being performed on the clinical effects of CSF in phase-ll studies. In addition to the flare response of metastases, increased uptake in the axial skeleton and/or juxta-articular areas on bone scintigraphy in five patients receiving CSF has been observed. This new phenomenon could be explained by a reaction to a very cellular marrow caused by the use of CSF. The clinical relevance of this finding remains to be established.The authors present an overview of these old and new phenomena seen on the bone scan with clinical and roentgenologic correlation.

ISSN:0363-9762    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Three-phase Tc-99m MDP scans of 61 patients with asymptomatic upper extremities randomly mixed with 17 studies of patients previously diagnosed with reflex sympathetic dystrophy were blindly interpreted by three observers. Asymmetry in any of the phases was recorded and a final diagnostic impression made.Thirteen of 17 reflux sympathetic dystrophy studies were rated abnormal by at least two observers. Mild to striking asymmetry was occasionally seen in all three phases in asymptomatic upper extremities. Twenty of 61 asymptomatic patients (33%) were rated abnormal by at least one observer, and 5 of 61 studies (8%) were rated abnormal by all observers. Asymmetries in normal patients occurred more commonly in the earlier phases, while asymmetry in the delayed images was mild in all but one. Tightening the criteria to exclude mild asymmetry in delayed images resulted in unacceptably low sensitivity for reflex sympathetic dystrophy (29%). Interob-server variability was most prominent in the flow and immediate images.In the diagnosis of reflex sympathetic dystrophy a greater reliance should be placed on the delayed images, which in themselves have an overall sensitivity of 94%. It is important, however, to recognize that occasional mild and rare moderate asymmetries in even the delayed images of normal individuals result in an overall lower specificity of 77%.

ISSN:0363-9762    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

A case of trauma-induced pancreatitis with subsequent intraosseous fat necrosis and infarction is presented. The young patient demonstrated multiple cortical lytic lesions of the lower extremities and bilateral sterile joint effusions. Several radiographic modalities were employed in the workup of his disease. Related findings and pathophysiologic considerations are reviewed.

ISSN:0363-9762    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Multifocal bone involvement was seen on bone scintigraphy in a young woman being examined for a suspected bone lesion noted on pelvic radiographs. Biopsy of the third lumbar vertebral body demonstrated a vascular lesion. The tumor was resected and a bone graft was performed. The patient was followed with serial scans to assess the viability of the bone graft and course of the disease. This report analyzes the scintigraphic characteristics of this rare tumor and emphasizes the importance of bone scintigraphy in the diagnosis, treatment, and follow up of this condition.

ISSN:0363-9762    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Myocardial SPECT using teboroxime was compared to thallium SPECT in 26 patients undergoing cardiac catheterization. Agreement between thallium SPECT and teboroxime SPECT for the identification of myocardial segments was 209/235 (89%). A significant correlation was found in 15 patients between the left ventricular ejection fraction by teboroxime first-pass study and the ejection fraction by contrast ventriculography. In nine patients with myocardial infarction and/or multivessel coronary artery disease, the ejection fraction revealed a mean decrease from 0.52 at rest to 0.46 at exercise. Teboroxime makes it possible to perform an exercise first-pass study of left ventricular ejection fraction followed by myocardial perfusion imaging.

ISSN:0363-9762    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Several methods are available for performing radionuclide stress myocardial perfusion studies. All of these methods require two separate acquisition and processing iterations, which is time-consuming and inconvenient for the patient. The authors introduce a new method using the “three window technique” that they developed to perform simultaneous dual-isotope imaging for stress myocardial perfusion studies. In addition to TI-201 and Tc-99m windows centered at 70 KeV and 140 KeV, respectively, a third window centered at 105 KeV, representing scattered radioactivity from Tc-99m, is established. By subtracting the radioactivity in the third window from the radioactivity in the TI-201 window, “crosstalk” interference is significantly reduced. The simultaneous dual-isotope imaging method acquires and processes resting and stress myocardial perfusion images simultaneously. It halves imaging time and doubles patient throughput, improves scheduling flexibility, and reduces patient waiting time and discomfort.

ISSN:0363-9762    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Two unusual examples of cardiac uptake in elderly patients who had received serial bone scans, one with a “waxing” and the other with a “waning” pattern of myocardial tracer uptake, are presented. An apparent temporal discordance between echocardiographic and scintigraphic findings is noted. Neither of the two patients had clinical, electrocardiographic, or other laboratory evidence of old or new myocardial infarction. Possible causes for the temporal changes are described. Presumptive diagnoses of senile cardiac amyloidosis were made based on clinical findings, noninvasive imaging, and comparison with a historic cohort at the Veterans Administration Medical Center in Houston.

ISSN:0363-9762    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Nonvisualization of the gallbladder associated with the rim sign of enhanced pericholecystic hepatic activity has been established as a useful and highly specific sign of acute cholecystitis. This study's purpose was to determine the pathophysiologic cause of the rim sign. Thirty- seven surgery-bound patients with a clinical diagnosis of acute cholecystitis were studied. A group of 20 patients with a definite rim sign were compared to a group of 17 patients without a rim sign; all with nonvisualization of the gallbladder. Radionuclide, surgical, and pathologic findings were correlated.In patients with the rim sign and in those without the rim sign, microscopic review of all surgical specimens revealed transmural reaction of the gallbladder wall in 95% and 59% of cases, respectively. The surgeon found inflammation extending beyond the gallbladder wall in 75% of rim sign cases, but in only 35% of case without the rim sign. Liver tissue was attached to the gallbladder specimen in three cases, and the findings support the association of hepatic inflammation with the presence of a rim sign.Pathologic correlation and surgical evidence suggest that the rim sign is caused by the spread of inflammation through the gallbladder wall and into adjacent liver tissue. Transmural reaction is required before the inflammatory process can reach the liver. A high-count, high-intensity technique seems to best demonstrate the rim sign. Once demonstrated, further delayed imaging is unnecessary.

ISSN:0363-9762    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

Biliary scans of 84 hospitalized patients believed to likely have acute cholecystitis, including 55 scans that had a radionuclide angiography phase, were retrospectively evaluated to determine the frequency of the rim sign and hyperperfusion, and to test the hypothesis that more intense hyperperfusion or rim sign is associated with a greater severity of gallbladder pathology ( “complicated” acute cholecystitis). In 65 of the 84 cases there was surgical intervention (including 43 from the 55 cases whose scans had a radionuclide angiography phase). “Complicated” acute cholecystitis was considered present if there was gangrene, perforation, empyema, necrosis, ulceration, or fibrous exudation. Each scan was evaluated for the presence of a rim sign and arterial hyperperfusion to the region of the gallbladder fossa. The intensities of these secondary signs of acute cholecystitis were then graded as “mild” or “marked.” Subdividing the rim sign and hyperperfusion into a “marked” category considerably improved the specificity, positive predictive value, and likelihood ratio (positive) for the diagnosis of acute cholecystitis, but even more so for the complicated subgroup when marked hyperperfusion or marked rim sign were the criteria used for a positive study. Approximately 50% of the patients with acute cholecystitis had hyperperfusion and a rim sign, and approximately 15% had marked hyperperfusion and a marked rim sign. Of the patients with acute cholecystitis, the only ones with marked hyperperfusion or a marked rim sign were those who had complicated acute cholecystitis. The data demonstrate an association between greater intensity of the rim sign or hyperperfusion and greater severity of gallbladder pathology in patients with acute cholecystitis. Nevertheless, identification of a mild degree of the rim sign or hyperperfusion also appears to be of clinical significance.

ISSN:0363-9762    

出版商:OVID    

年代:1993

数据来源: OVID

摘要:

The authors reviewed 50 pediatric patients (56 renal units) who underwent pyeloplasty and had serial preoperative and postoperative diuresis renogram and ultrasound studies. Of those patients that clinically improved with surgery, 73% and 91% showed improved renographic patterns in postoperative studies at 3 and 12 months, respectively. Ultrasound demonstrated more gradual improvement in grade and pelvic diameters over longer study intervals. Diuresis renography is an excellent predictor of surgical outcome within 3 months of pyeloplasty and showed change well in advance of that seen on ultrasound. Sonography is better suited to longer term evaluation of grade, pelvic diameter, and renal size.

ISSN:0363-9762    

出版商:OVID    

年代:1993

数据来源: OVID